On this day in 1945, the United States dropped the atomic bomb on the Japanese city of Hiroshima. This was the first use of a nuclear weapon in the history of war; followed only by the bombing of Nagasaki three days later.
World War II had effectively come to a close in Europe on 8 May, with the surrender of Nazi Germany. However the war continued in the Pacific and East Asia.
Beginning in October 1944, the United States had carried out a sustained air campaign against Japan: in the six months from January 1945, under the command of Major General Curtis LeMay, American bombers targeted sixty-seven Japanese cities, with the Bombing of Tokyo on 9-10 March alone killing 100,000. The Japanese economy had been devastated. But the country refused to surrender to the Allies, rejecting the Potsdam Declaration issued on 26 July – despite its ultimatum which stated that if Japan did not surrender, it would face ‘prompt and utter destruction’.
The Allies had previously prepared to enact Operation Downfall: the plan, orchestrated by the United States, for the invasion of Japan. It was to commence in October with Operation Olympic, a landing of US troops on Kyushu, the most southern of Japan’s four main islands. Once taken, Kyushu would serve as a staging point for Operation Coronet and an advance towards Tokyo.
Yet based partly on the ferocious Battle of Okinawa, various estimates suggested that the invasion of Japan could result in anything from tens-of-thousands to four-million American casualties; with the potential for the death of half a million Americans, and five-to-ten million Japanese.
Thus in the face of Japanese persistence, before the Potsdam Declaration had been issued, plans for the atomic bombings had been finalised. United States Secretary of War Henry L. Stimson and President Harry S. Truman had agreed on Hiroshima and Kokura as the targets, sparing Kyoto and Tokyo, the old and new capitals of Japan.
On 25 July, President Truman noted in his diary:
‘This weapon is to be used against Japan between now and August 10th. I have told the Sec. of War, Mr. Stimson, to use it so that military objectives and soldiers and sailors are the target and not women and children. Even if the Japs are savages, ruthless, merciless and fanatic, we as the leader of the world for the common welfare cannot drop that terrible bomb on the old capital [Kyoto] or the new [Tokyo]. He and I are in accord. The target will be a purely military one.’
What became the Manhattan Project – the US-led research initiative towards producing the world’s first nuclear weapons – began life in 1939. With collaboration from the United Kingdom and Canada, from 1942 the project was headed by the physicist J. Robert Oppenheimer, based at the Los Alamos National Laboratory in New Mexico.
On 16 July 1945, the first nuclear test, codenamed Trinity, was successfully conducted in the Jornada del Muerto desert, southeast of Socorro, New Mexico. ‘Little Boy’, a gun-type fission weapon, and ‘Fat Man’, an implosion-type nuclear weapon, arrived at North Field – the US airbase on Tinian in the Mariana Islands – at the beginning of August.
At the time Hiroshima remained an important industrial city for Japan, and the headquarters of several prominent military units. The population of the city at stood at around 350,000.
The ‘Little Boy’ bomb was dropped on downtown Hiroshima at 08:15 local time on 6 August. At least 70,000 people, including 20,000 Japanese soldiers, were killed instantly by blast, with roughly the same number injured. The death toll would double over the coming weeks. Officials later determined that 69% of Hiroshima’s buildings had been destroyed.
Two days later, on the evening of 8 August, in violation of the Soviet-Japanese Neutrality Pact, the Soviet Union declared war on Japan. The following day they invaded; and later on 9 August, the United States dropped their second atomic bomb, on Nagasaki, their secondary target after cloud and smoke had obscured Kokura. Finally the surrender of the Empire of Japan was announced on 15 August.
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Today residents of Hiroshima commemorated the 70th anniversary of the bombing. 40,000 people, including foreign delegates, gathered in Hiroshima Peace Memorial Park, observing a nationwide minute’s silence at 08:15. They were then addressed by Prime Minister Shinzo Abe and Mayor Kazumi Matsui.
Praising the revived city, Abe stated that Hiroshima has again ‘become a city of culture and prosperity’. He continued, ‘Seventy years on I want to re-emphasise the necessity of world peace’. For his part Matsui urged worldwide nuclear disarmament, calling nuclear weapons an ‘absolute evil’, and saying:
‘To coexist we must abolish the […] ultimate inhumanity that is nuclear weapons. Now is the time to start taking action.’
Incense was burned in the city; doves were released over the park’s A-Bomb Dome; and in the evening thousands of coloured paper lanterns were released onto the Motoyasu River.